Field of the Invention
The present invention relates to a vehicle understructure in which an underpanel is provided in the lower portion of a vehicle, and the lower surface of the vehicle is formed by the underpanel.
Description of the Related Art
As a vehicle understructure, a structure is known in which an underpanel is provided in the lower portion of a vehicle, and an undercover is supported on the lower side of the underpanel to be movable in the vertical direction. The undercover is supported on the lower side of the underpanel. The whole area of the underpanel is covered from below by the undercover. That is, the undercover is formed flat all over the lower portion of the vehicle.
According to this vehicle understructure, a negative pressure is generated under the undercover (that is, in the space between the undercover and the road surface) during driving of the vehicle (more specifically, during driving at a medium or high speed). The generated negative pressure can lower the undercover. By lowering the undercover to make the ground clearance of the vehicle low, the negative pressure is satisfactorily generated between the undercover and the road surface. The stability of the vehicle is thus ensured (for example, see Japanese Patent Laid-Open No. 2009-220689).
In the vehicle understructure disclosed in Japanese Patent Laid-Open No. 2009-220689, however, the undercover is formed flat all over the lower portion of the vehicle, and the flat undercover can wholly be lowered. It is therefore difficult to suitably reduce an air resistance generated by an airflow that occurs during driving of the vehicle. From this viewpoint, there is still room for improvement.
It is an object of the present invention to provide a vehicle understructure capable of suitably reducing an air resistance.